Plier-type hand tool



F. l. TALLENTIRE ETAL PLIER-TYPE HAND TOOL Filed Sept. 5, 1963 2 Sheets-Sheet 1 34 14 5a 56 n 26 22 32 1 62 3o 42 I8 44 2O 66 6} 60 I8 20 A 48 H 40 76 I o Fm. 4. 44 J 3 76. 6.

6 46 54 5O INVENTORS FRANCIS l. TALLENTIRE RICHARgY H. FROST ATTORNEYS fie. i

March 1966 F. TALLENTIRE ETAL ,2

PLIER-TYPE HAND TOOL Filed Sept. 5, 1963 2 Sheets-Sheet 2 INVENTORS 1 6. 70. FRANCIS l. TALLENTIRE RICHARD H. FROST ATTORNEYS United States Patent 3,238,763 PLIER-TYPE HAND TOOL Francis I. Tallentire, Aurora, and Richard H. Frost, Bow

Mar, Colo., assignors to Frost Engineering Development Corporation, Englewood, Col0., a corporation of Colorado Filed Sept. 5, 1963, Ser. No. 306,930 8 Claims. (Cl. 72429) This invention relates to a plier-type hand tool and, more particularly, to a hand-operated capping tool specifically designed for use in the application of protective caps to animal teeth.

Considerable attention has been focused in recent years on the problem of the excessive wear produced on cows teeth when they feed upon open range containing abrasive grasses, plants and soil. In certain sections of the country, this problem is more serious than in others, however, where it does occur, the useful life of a range cow is often determined by the condition of her teeth. Accordingly, steps have been taken to extend the useful life of a range cow experiencing excessive tooth wear by fitting the teeth with metal protective caps.

Some of these cap designs are such as to require each to be individually fitted to a particular tooth by specially trained persons much in the same way as a human tooth is capped. An adjustable cap has recently become available commercially that will fit teeth of varying sizes and shapes without modification. While such a cap possesses many advantages, perhaps the most significant one is that when mounted by means of a tool made especially for this purpose, no extraordinary skill or training is required and the entire operation can, therefore, be carried out by non-professional personnel. It is to such a capping tool that the present invention relates.

Speed, simplicity of operation and dependability are three prime requisites of such a tool. Speed because the capping operation must be performed very rapidly to prevent the cement from drying before the cap is in place and also because the animal is not going to hold still very long. skilled ranch hands are going to be charged with responsibility for mounting the caps and it must be dependable to insure a proper fit that will stay in place under the conditions of hard use to which it will be subjected. There are, of course, other requirements of lesser significance such as, for example, the provision of a structure that can be taken apart readily for cleaning and sterilization.

The capping tool of the present invention satisfies these requirements by providing a hand-operated plier-type tool with a sliding jaw that moves forwardly with a reciprocating action across a downwardly facing opening within which the cap is inserted. The jaws are normally biased into closed position by a spring which urges the movable handle toward the fixed one. The opening separating the jaws, by facing downwardly rather than forwardly as is the usual situation, permits the tool to be held horizontal while the cap is being affixed. The reciprocating action of the jaws acts to telescope the elements of the cap onto the tooth regardless of its size. Disassembly of the tool to remove encrusted cement, dirt and other contaminants is quite easily accomplished Without any tools being required. The entire tool is made of metal, preferably stainless steel that provides a smooth finish so that it can be sterilized quite easily.

Intermediate the fixed and movable jaws, the fixed handle is provided with a narrowed section which is quite useful. First of all, the top of the cap remains visible alongside the aforementioned narrowed section during the entire capping operation which facilitates proper po- The tool must be easy to operate it unsitionin'g thereof in the confined space inside the cows mouth. Also, the cement is applied to the inside of the cap while the latter is held between the jaws of the tool when turned upside down. The likelihood is that some cement will find its way onto that portion of the fixed handle lying between the jaws. If this occurs, the excess cement will drip onto the outside surfaces of the narrowed section where it is easily removed rather than some interior surface of the tool that would be difficult to clean and might even result in the movable jaw being cemented to the fixed handle.

The unique jaw design of the capping tool is another feature that deserves special consideration. The cow teeth being capped obviously vary considerably in both size and shape. While the telescopic construction of the cap provides ample adjustment for variations in size of the tooth, the capping tool must perform a certain amount of deformation of the downturned tabs to shape the latter so as to mate snugly with the corresponding surface of the tooth. Also, one or both of the jaws should include some yielda'ble feature which would prevent the tooth from breaking or becoming chipped upon the application of excessive force. The above features are realized in the fixed jaw which provides a pair of transverse ly-aligned incurled spring fingers that engage the front downturned tab of the cap and, upon the application of closing pressure, slide apart along the face of said tab with a wiping action to shape same in conformity with the adjacent tooth surface thereby insuring a near-perfect fit. Then, should excessive pressure he applied, the fixed jaw can spread further apart until the spring fingers move onto the sides of the tooth thus preventing the excess force from damaging the latter.

In a modified form of the tool which is also included herein, the spring fingers of the fixed jaw are joined together and do not spread apart to the extent required to prevent overloading of the tooth. Here, however, a second or overload spring engages the movable jaw and allows same to yield upon the application of excessive pressure on the handles.

The cap-engaging portions of both jaws are inclined upwardly and away from the cap to improve visibility and also to minimize the contact areas between the tool and cap that are likely to become encrusted with excess cement. The cement used on the caps is generally of the epoxy type that is most difiicult to remove once it dries which explains the precautions taken to keep it off the tool insofar as is practicable. The quick disassem bly of the tool for cleaning is, of course, necessary to facilitate removal of encrusted cement.

It is, therefore, the principal object of the present invention to provide a novel plier-type capping tool particularly suited for use in applying protective caps of the telescoping type to animal teeth.

A second object is the provision of a tool of the type aforementioned that requires the operator to use only one hand in fastening the cap to the animals tooth.

Another object of the invention herein claimed is to provide a capping tool that simultaneously shapes and fastens the cap onto the tooth.

Still another object is to produce a tooth-capping tool that will accept caps of different sizes and fasten them on teeth of varying sizes and shapes.

An additional objective is the provision of plier-type hand tool that utilizes a unique sliding jaw arrangement which is ideally suited to applications requiring a crimping action.

Further objects of the invention are to provide a plierlike capping tool that is simple to use, lightweight, rugged, versatile, compact, easy to clean, inexpensive and decorative in appearance.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows, and in which:

FIGURE 1 is a side elevation of the capping tool showing the jaws in fully closed position, portions of the fixed handle having been broken away and shown in section to better reveal the interior construction;

FIGURE 2 is a fragmentary section taken along line 2-2 of FIGURE 1;

FIGURE 3 is a side elevation similar to FIGURE 1 except that the jaws are farther open and portions of the movable jaw and movable handle have also been broken broken away and shown in section to clearly reveal the sliding connection;

FIGURE 4 is a vertical section taken along line 44 of FIGURE 1 and slightly enlarged;

FIGURE 5 is a fragmentary side elevation of the jaws showing a protective cap in place therebetween and the action of the jaws in shaping and telescoping same;

FIGURE 6 is a vertical section taken along line 66 of FIGURE 5 showing the shape of the fixed jaw slightly enlarged;

FIGURE 7 is a side elevation similar to FIGURE 3 with portions broken away and shown in section illustrating a modified form of the capping tool;

FIGURE 8 is a fragmentary detail of the movable handle showing the means for retaining the strain relief spring;

FIGURE 9 is a section taken along line 9-9 of FIG- URE 8; and,

FIGURE 10 is a section taken along line 1010 of FIGURE 7.

Referring now to the first four figures of the drawing for a detailed description of the capping tool which has been designated in a general way by reference numeral 10, it will be seen to include a fixed handle 14, a movable handle 12 pivotally attached to the fixed handle, a spring 16 biasing the handles into closed position, a movable jaw 18 carried by the fixed handle for slidable movement toward and away from the fixed jaw 20 in response to actuation of the movable handle, and a keeper 22 that detachably fastens the movable jaw to the fixed handle. The fixed handle 14 is generally channel-shaped metal stamping that provides a rearwardly-extending portion 24 intended to be grasped by the fingers of the users hand in the same manner as a pair of pliers. The opening in the channel faces upwardly and is bounded by laterallyspaced substantially parallel wall portions 26 located forward of the finger-hold 24 to define supports for the movable handle 12. A pivot pin 28 spans the gap between wall portions 26 of the fixed handle and provides the pivotal mounting for the movable handle 12 as well as point of attachment for spring 16.

Spaced below the pivot pin 28, wall portions 26 of the fixed handle are provided with transversely aligned elongate slots 30 that parallel the bottom of the channel. These slots accept a pair of longitudinally spaced pins 32 which fasten the movable jaw 18 to the fixed handle for longitudinal slidable movement toward and away from the fixed jaw 20 on the extreme forward extremity of the fixed handle.

Between the wall portions 26 and the fixed jaw 20 of the fixed handle 14 is a section of reduced width 34 that lies immediately above the downwardly opening recess 36 that receives the protective cap or other work piece 38 (FIGURE 5). In other words, the web 40 that connects the sidewalls of the channel in the fixed handle 14 is cut away beneath narrowed section 34 and ahead of slots 30 to produce recess 36. Actually, this recess 36 extends part way up the sides of the channel to define narrow ledges 42 against which the work piece 38 rests when retained between the fixed and movable jaws. As aforementioned, these narrow ledges expose the top of the cap to the view of the user and, therefore, facilitate installation of the cap in the small interior of the cows mouth. Also, the cement from the cap which escapes onto the tool will be deposited on the outside of narrowed section 34 where it is easily removed. Note also that movable jaw 18 passes underneath narrowed section 34 due to recess 36 and in spaced relation to the sides thereof where it is unlikely to pick up any cement that may have lodged on this section of the movable handle.

Briefly with reference to FIGURES 5 and 6 where the construction of the fixed jaw 20 is best revealed, it will be seen that web 40 in the bottom of the fixed handle 14 is slit longitudinally from recess 36 forwardly to free a pair of springable tabs 44 that are upturned to form abutments positioned to engage the downturned section 46 of the cap and shape same against the rear face of the tooth being capped. These tabs 44 lie at the open front end of the fixed handle as best seen in FIGURE 2 and are, therefore, at liberty to move apart under the influence of a spreading pressure. Thus, when these tabs engage the convex surface 46 of the cap as seen in FIG- URE 5 and are drawn tightly thereagainst, said tabs tend to spring apart and slide along convex face 46 deforming the latter so that it conforms with the inside surface of the tooth (not shown). This fixed jaw 20 is, of course, hooked over the back or inside of the tooth while the movable jaw 18 is actuated to telescope element 48 of the protective cap forwardly until it engages the exposed tooth face. The cap-engaging front edge 50 of the movable jaw is curved, as best seen in FIGURE 2, to receive the other downturned section 54 of the cap and form the latter against the tooth. A cement is used on the inside surfaces of the cap to fasten it securely in place. Note that the narrowed section 34 of the fixed handle overlies the working surface 56 of the cap and functions to hold it down on top of the tooth.

Next with reference to FIGURES 1, 2 and 4, it can be seen that the movable jaw 18 is likewise channel-shaped and sized to accept the slightly narrower channel formed by the fixed handle 14 therein for slidable movement part way across aperture 36. Pins 32 passing across between the parallel sides 58 and 60 of the movable jaw mount the latter for longitudinal slidable movement on the fixed handle as these pins pass through the transversely aligned slots 30. Note that the leading edge of the movable jaw is inclined rearwardly so that the inside surfaces of the channel walls 58 and 60 have very little sliding contact with the opposing faces of the fixed handle adjacent the narrowed section 34 thereof that are most likely to become coated with excess cement. Thus, there is little likelihood that the movable jaw will become cemented to the fixed handle. Also, as the movable jaw moves forwardly, its sides and bottom pass in spaced relation to opposing portions of the fixed handle due to recess 36 and narrowed section 34. This, of course, substantially eliminates any possibility that the movable jaw will pick up any excess cement deposited on the fixed handle.

Pins 32 have a large head 61 on one end and a small head 62 on the other that is the same diameter as the shank and is separated therefrom by annular groove 66. Keeper plate 22 contains a keyhole-shaped slot 68 that will pass head 62 through the circular portion thereof, yet, will prevent the head from passing through the narrower section when the latter is located in the annular groove 66 as shown in FIGURES 2 and 4. The annular groove in the front pin receives a semi-circular notch (not shown) in the forward edge of the keeper. To hold the keeper in place as shown in FIGURE 1, an indentation 70 is provided in the face thereof which drops into a hole 72 (FIGURE 2) in the side wall 60 of the movable jaw. By sliding the keeper to the rear or to the right as seen in FIGURE 1, the pins can be withdrawn and the movable jaw separated from the fixed handle. This occasionally becomes necessary in order to remove dried cement left on the jaw surfaces from the capping operation.

The movable handle 12 is channel-shaped as is the fixed handle 14 as can be seen in the first four figures of the drawing to which reference will once again be made. The movable handle channel opens downwardly toward that of the fixed handle and is narrower so as to fit between wall portions 26 of said fixed handle and swing freely on pivot pin 28. The palm engaging portion 74 of movable handle 12 is substantially coextensive with the analogous portion 24 of the fixed handle. The over-all length of the movable handle is, however, considerably shorter than that of the fixed handle, the former terminating at pivot 28 for all practical purposes.

As aforementioned, the pivot pin 28 is located in spaced relation above the slots 30 in the fixed handle. Formed integral with the movable handle at the forward end thereof are a pair of lever arms 76 that extend from pivot pin 28 downwardly across the slots 30 in the fixed handle and between the pins 32 in the movable jaw as shown most clearly in FIGURE 3. These lever arms 76 function upon movement of the movable handle 12 from the open or unactuated position of FIGURE 3 into the closed or actuated position of FIGURE 1 to slide the movable jaw forward toward the fixed jaw as said lever arms engage the front pin 32 and move it ahead in slot 30. Obviously, only one lever arm is needed to accomplish this function but it is just as simple to stamp out the movable handle with two and they have the advantage of applying the crimping force on both sides of the longitudinal centerline of jaw 18 thus eliminating any tendency for the latter to bind or become canted. The free ends 78 of the lever arms 76 are rounded as shown to produce a constant and substantially uniform motion in the movable jaw.

The limit to the forward excursion of the movable jaw is determined by a pair of stops 80 that extend downwardly from the movable handle at points spaced rearwardly from pivot 28. These stops 80 are formed integral with the handle and are adapted to contact the web 40 that lies in the bottom of the fixed handle channel when the movable jaw has moved forward to the position of FIGURE 1. This maximum closure of the jaws corresponds to the minimum length of the cap realized when the elements thereof are fully telescoped. Here again, a single limit stop 80 will accomplish the same end result as a pair thereof but two give added strength and are no more diificult to manufacture.

In FIGURE 3 it will be seen that the rear limit to the excursion of the movable jaw is determined by rear pin 32 coming to the end of slot 30. It would, of course, be possible to eliminate stops 30 and let the front pin 32 come to the end of slot 30 to limit the forward excusion of the movable jaw by making minor adjustments in the slot length or pivot pin location.

Next, with reference to FIGURES 3 and 4, it will be seen that spring 16 has the intermediate portion thereof coiled around pivot pin 28 and legs 82 and 84 connected respectively to the fixed and movable handles. Openings 86 are provided in the webs of the channel-shaped handles sized to accept and retain the hooked ends 88 on the legs. These legs bias the handles toward one another so as to extend the movable jaw 18 in the direction of the fixed jaw 20. The reason for this action is that the jaws can then function to retain the cap in place therebetween even though no pressure is applied to the handles by the user. This self-retention of the cap is advantageous while inserting the tool into the animals mouth and performing other operations incidental to this capping procedure.

In the above-described embodiment of the capping tool, the strain relief necessary to prevent undue pressure from being brought to bear on the tooth is provided by the spreadable spring jaw 44. Referring now to FIG- URES 7-10, inclusive, it will be seen that another type of overload-release is provided on the modified capping tool which has been broadly designated by reference numeral 10m. Here the fixed handle 14m has the fixed jaw 20m thereof modified such that the upturned tabs 44m have their free ends connected to form a unitary structure. By so doing, the fixed jaw is still able to spring apart slightly as the bends therein tend to straighten out thereby performing the desired wiping action against the cap; however, it will not yield to the point where the tabs can pass alongside the tooth upon the application of excessive force. The remaining elements of the fixed handle are substantially unchanged as indicated by the use of the same reference characters found in FIGURES 1-6, inclusive.

The movable jaw 18 is essentially the same as before and is mounted on the pins 32 for reciprocal movement in the slots 30. The movable jaw is detachably connected to the pins in the same way and it functions similarly in cooperation with the fixed jaw 20m.

The movable handle 12m, on the other hand, has undergone substantial modification to accommodate the overload spring 90. To begin with, the lever arm is foreshortened and otherwise shaped so that it no longer bears against the front pin 32 thus providing the means for urging the movable jaw forwardly. Its function is, therefore, simplified in that it merely engages the rear pin to retract the movable jaw. Stop 89, on the other hand, retains its same shape and function as does spring 16.

With particular reference to FIGURES 7, 8 and 9, it will be seen that the free rear end of the heavy overload spring 90 is crimped into place against the web 92 of the channel-[shaped movable handle by opposed inwardlyextending slightly elongated depressions 94 formed in the sides of the movable handle channel in position to engage the underside of said spring and force same upwardly. Thus, the rear extremity of spring 90 is frictionally clamped into the top inside of the movable handle.

The intermediate portion of spring 90 is bent downwardly and forwardly over pin 28 and the forward extremity 96 thereof terminates between the movable-jaw supporting pins 32. The forward end 96 of spring 90 is curled rearwardly and upwardly to provide a surface of substantially the same shape as the lower end of lever arm 76 in the previous design. Functionally, spring 90 performs the same function as formerly accomplished by lever arm 76 insofar as urging the movable jaw toward closed position when the movable handle is grasped and moved toward the fixe/l one. The stiffness of spring 90 is such as to transmit the force to movable jaw 18 that it is necessary to telescope and form the cap around the tooth. It performs the additional function, however, of allowing the movable jaw to yield upon the application of excessive pressure such as that which might crack or break the tooth.

Having thus described the several useful and novel features of the capping tool of the present invention, it will be seen that the many worthwhile objectives for which it was developed have been achieved. Although but two specific embodiments of the tool have been illustrated and described, we realize that certain changes and modifications therein may well occur to those skilled in the art within the broad teaching hereof; hence, it is our intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims.

What is claimed is:

1. The plier-type hand tool which comprises, a fixed handle having a first downwardly projecting jaw at its forward extremity that faces to the rear, a second forwardly facing jaw suspended from the underside of the fixed handle for substantially straight-line sliding motion toward the first jaw, said jaws cooperating upon actuation of the second jaw in a direction to move same toward the first to retain and squeeze a work piece placed therebetween, a movable handle connected to the fixed handle for plierlike motion relative to the latter about a transverse axis of pivotation located above the second jaw, and a crank arm means extending downwardly from the movable handle in operative association therewith adapted upon movement of the latter toward the fixed handle to engage the second jaw and slide same forwardly wherein at least the first jaw located at the forward extremity of the fixed handle is bifurcated and fabricated from springable metal, each half of said bifurcated first jaw including transversely aligned incurled portions adapted to engage a convex surface of a work piece and deform the latter with a wiping action as they spread apart under the influence of the jaw-closing pressure, said bifurcated first jaw also providing a yieldable overload release whereby said incurled portions can spread apart and release the work piece upon the application of excessive jaw-closing forces.

2. The plier-type hand tool as set forth in claim 1 in which, the fixed handle comprises an upwardly opening channel having transversely aligned longitudinal slots intermediate the ends thereof in spaced parallel relation above the lower edge, the second jaw comprises an upwardly opening channel-shaped element adapted to envelop the fixed handle and cover both longitudinal slots therein, said second jaw having a pair of longitudinallyspaced pins interconnecting the sides thereof through said longitudinal slots thereby mounting said jaw for longitudinal slidable movement, and in which the crank arm depending from the movable handle passes between the pins of the second jaw thus providing means for effecting reciprocal motion of the latter.

3. The plier-type hand tool as set forth in claim 2 in which the fixed handle is provided with a recess in the underside thereof immediately behind the first jaw across which the second jaw moves in spaced relation toward closed position.

4. The plier-type hand tool as set forth in claim 1 in which the section of the fixed handle located between the first jaw and the retracted 'position of the second jaw is narrowed and substantially narrower than the said second jaw so that the latter passes in spaced relation thereto as it moves toward closed position.

5. The plier-type hand tool as set forth in claim 2 in which the upwardly opening channel of the fixed handle includes upstanding substantially parallel sidewalls connected together along their bottom edges by a transverse Web, that portion of said connecting web position ahead of the second jaw when the latter is fully retracted being cut away to define a recess, and those portions of the sidewalls lying above said recess being closer to one another than the remainder of said sidewalls to provide supporting surfaces adapted to engage the top surface of a work piece retained between the jaws.

6. The plier-type hand tool as set forth in claim 2 in which, the movable handle comprises a downwardly opening channel of an over-all width adapted to fit inside the upwardly-opening channel of the fixed handle.

7. The plier-type hand tool which comprises, a fixed handle having a first downwardly projecting jaw at its forward extremity that faces to the rear, a second forwardly facing jaw suspended from the underside of the fixed handle for substantially straight-line sliding motion toward the first jaw, s'aid jaws cooperating upon actuation of the second jaw in a direction to move same toward the first to retain and squeeze a work piece placed therebetween, a movable handle connected to the fixed handle for plier-like motion relative to the latter about a transverse axis of pivotation located above the second jaw, and a crank arm means extending downwardly from the movable handle in operative association therewith adapted upon movement of the latter toward the fixed handle to engage the second jaw and slide same forwardly wherein the first jaw located at the forward extremity of the fixed handle is bifurcated and fabricated from springable metal each half of said bifucated first jaw including work engaging portions adapted to engage a convex surface of a work piece and deform the latter with a wiping action as they spread apart under the influence of the jaw-closing pressure, said bifurcated first jaw also providing a yieldable overload release whereby said work engaging portions can spread apart and release the work piece upon the application of excessive jaw-closing forces.

8. The pliertype hand tool which comprises, a fixed handle having a first downwardly projecting jaw at its forward extremity that faces to the rear, a second forwardly facing jaw suspended from the underside of the fixed handle for substantially straight-line sliding motion toward the first jaw, said jaws cooperating upon actuation of the second jaw in a direction to move same toward the first to retain and squeeze a work piece placed therebetween, a movable handle connected to the fixed handle for plier-like motion relative to the latter about a transverse axis of pivotation located above the second jaw, spring means operatively interconnecting the handles and normally biasing same into closed position and a crank arm means extending downwardly from the moveable handle in operative association therewith adapted upon movement of the latter toward the fixed handle to engage the second jaw and slide same forwardly wherein the crank arm means comprises a second spring carried by the movable handle with a portion thereof operatively connected to the movable jaw, said second spring being adapted to yield at a pre-determined jaw pressure thus limiting the clamping force exerted therebetween to a value that will not damage the work piece.

References Cited by the Examiner UNITED STATES PATENTS 134,440 12/1872 Roache 81-361 X 259,895 6/1882 Miller 81-356 908,947 1/1909 Burkhart 81-417 X 1,326,820 12/1919 Youdelman. 1,391,898 9/1921 Kettler 81-361 1,555,652 9/1925 Frame. 2,375,512 5/1945 Baade 81-341 X 2,546,616 3/1951 Schaaff 81-416 X 2,827,815 3/1958 Smoyak 81-417 2,985,047 5/1961 Van Oort 81-341 X WILLIAM FELDMAN, Primary Examiner. MICHAEL BALAS, Examiner, 

1. THE PLIER-TYPE HAND TOOL WHICH COMPRISES, A FIXED HANDLE HAVING A FIRST DOWNWARDLY PROJECTING JAW AT ITS FORWARD EXTREMITY THAT FACES TO THE REAR, A SECOND FORWARDLY FACING JAW SUSPENDED FROM THE UNDERSIDE OF THE FIXED HANDLE FOR SUBSTANTIALLY STRAIGHT-LINE SLIDING MOTION TOWARD THE FIRST JAW, SAID JAWS COOPERATING UPON ACTUATION OF THE SECOND JAW IN A DIRECTION TO MOVE SAME TOWARD THE FIRST TO RETAIN AND SQUEEZE A WORK PIECE PLACED THEREBETWEEN, A MOVABLE HANDLE CONNECTED TO THE FIXED HANDLE FOR PLIERLIKE MOTION RELATIVE TO THE LATTER ABOUT A TRANSVERSE AXIS OF PIVOTATION LOCATED ABOVE THE SECOND JAW, AND A CRANK ARM MEANS EXTENDING DOWNWARDLY FROM THE MOVABLE HANDLE IN OPERATIVE ASSOCIATION THEREWITH ADAPTED UPON MOVEMENT OF THE LATTER TOWARD THE FIXED HANDLE TO ENGAGE THE SECOND JAW AND SLIDE SAME FORWARDLY WHEREIN AT LEAST THE FIRST JAW LOCATED AT THE FORWARD EXTREMITY OF THE FIXED HANDLE IS BIFURCATED AND FABRICATED FROM SPRINGABLE METAL, EACH HALF OF SAID BIFURCATED FIRST JAW INCLUDING TRANSVERSELY ALIGNED INCURLED PORTIONS ADAPTED TO ENGAGE A CONVEX SURFACE OF A WORK PIECE AND DEFORM THE LATTER WITH A WIPING ACTION AS THEY SPREAD APART UNDER THE INFLUENCE OF THE JAW-CLOSING PRESSURE, SAID BIFURCATED FIRST JAW ALSO PROVIDING A YIELDABLE OVERLOAD RELEASE WHEREBY SAID INCURLED PORTIONS CAN SPREAD APART AND RELEASE THE WORK PIECE UPON THE APPLICATION OF EXCESSIVE JAW-CLOSING FORCES. 